The antitrust laws prohibit conduct by a single firm that unreasonably restrains competition by creating or maintaining monopoly power. Most Section 2 claims involve the conduct of a firm with a leading market position, although Section 2 of the Sherman Act also bans attempts to monopolize and conspiracies to monopolize. As a first step, courts ask if the firm has "monopoly power" in any market. This requires in-depth study of the products sold by the leading firm, and any alternative products consumers may turn to if the firm attempted to raise prices. Then courts ask if that leading position was gained or maintained through improper conduct—that is, something other than merely having a better product, superior management or historic accident. Here courts evaluate the anticompetitive effects of the conduct and its procompetitive justifications.
"Market Power"
Courts do not require a literal monopoly before applying rules for single firm conduct; that term is used as shorthand for a firm with significant and durable market power — that is, the long term ability to raise price or exclude competitors. That is how that term is used here: a "monopolist" is a firm with significant and durable market power.
I didn't claim that Amazon was or wasn't a monopoly so I'm not following the point you're trying to make here. Centralization is not the same thing as monopoly.
The antitrust laws prohibit conduct by a single firm that unreasonably restrains competition by creating or maintaining monopoly power. Most Section 2 claims involve the conduct of a firm with a leading market position, although Section 2 of the Sherman Act also bans attempts to monopolize and conspiracies to monopolize. As a first step, courts ask if the firm has "monopoly power" in any market. This requires in-depth study of the products sold by the leading firm, and any alternative products consumers may turn to if the firm attempted to raise prices. Then courts ask if that leading position was gained or maintained through improper conduct—that is, something other than merely having a better product, superior management or historic accident. Here courts evaluate the anticompetitive effects of the conduct and its procompetitive justifications.
"Market Power"
Courts do not require a literal monopoly before applying rules for single firm conduct; that term is used as shorthand for a firm with significant and durable market power — that is, the long term ability to raise price or exclude competitors. That is how that term is used here: a "monopolist" is a firm with significant and durable market power.
https://www.ftc.gov/tips-advice/competition-guidance/guide-a...
What you may think has little relation to governing regulatory law.